Cellular communications systems generally support one or more cellular protocols that facilitate wireless connections between wireless devices or user equipment (UE) and cell towers operated by the cellular communications systems. Presently, these cellular communications systems may use earlier cellular protocols, such as 2G (e.g., EDGE) or 3G (e.g., CDMA 2000 and UMTS), and modern cellular protocols sometimes referred to as 4G long-term evolution (LTE). The modern cellular protocols support packet-switched voice and data communications over LTE, such as VoLTE, while the earlier cellular protocols involve circuit-switched cellular communications and do not support VoLTE. Many wireless devices capable of cellular communications are equipped to support operation using 2G, 3G, or 4G LTE cellular protocols.
The cellular system implementing these cellular protocols includes cells or cell towers that are spaced apart from other cell towers by a distance that corresponds to a communication range of handheld wireless devices using low-gain antennas. As a wireless device using a low-gain antenna moves toward the outer boundary or range of one cell, the boundary of another cell is nearby ready to provide service to the wireless device. When the wireless device leaves one cell and enters another, the device ends communication with a first cell tower and begins communicating with a second, adjacent cell tower. These transfers may begin in response to a determination that the wireless device has traveled beyond a communication range or footprint serviced by the first cell. To determine when to begin the transfer from one cell to another, the wireless device can detect the signal quality of the cell tower the device presently uses and decide to switch cells or cell towers when the signal quality falls below a predetermined threshold. At that point, the boundary of another cell meets or slightly overlaps the present cell and is ready to provide cellular service to the wireless device.
However, a number of variables can upset the effective movement of the wireless device between adjacent cells in the cellular system. While the cells may be optimized for wireless devices using low-gain antennas, other wireless devices may use relatively high-gain antennas that permit the wireless devices to receive cellular signals at a greater distance than wireless devices using low-gain antennas. The overlap may also be affected when adjacent cells use different cellular protocols. As cellular systems and individual cells have begun implementing different cellular protocols, the amount of overlap between cells can vary enough to interfere with the transfer of communications between adjacent cells in a cellular system.